The objective of this study is to assess the safety of the buprenorphine transdermal system (5, 10, and 20) in comparison to placebo transdermal system and immediate release oxycodone/ acetaminophen in subjects with chronic back pain. The double-blind treatment intervention duration is 84 days during which time supplemental analgesic medication (non-steroidal anti-inflammatory drugs) will be allowed for all subjects in addition to study drug.